So, I've made an OpenGL library that lets one do very complicated operations very easily.  The project, available here, normally works excellently.

On one of a user's computers, the function glLib/glLibMisc.py/glLibAlpha(alpha) hangs. 

After some deliberation, it was found that only certain functions cause the problem.  By now, we think that the problem may occur only when OpenGL's color-related functions are accessed. 

These operations in the function cause a hang:
     glGet*(GL_CURRENT_COLOR) #Tries to access the current color
     glColor4f(...) #changes the GL color
     sys.exit() #exits, of course
     pygame.quit() #closes the display

These (and related things) don't:
     glGetDoublev(GL_MODELVIEW_MATRIX) #doesn't access any colors
     len('abc') #nothing to do with OpenGL

A proper context has been set up with PyGame. 

Any idea what's going on?